The present invention relates to the field of animal care, and, more particularly, to devices for sheltering and protecting small animals from exposure to the outdoor elements.
Recent years have seen a proliferation of different sizes and shapes of doghouses, shelters, kennels, and cages. Most have been designed and marketed for small animals that spend most, of not all, of their lives outside. However, when weather conditions result in extremely cold temperatures, these houses and shelters offer little protection. This means that owners are often required to make other arrangements for their small animals such as brining them indoors and placing them in uncomfortably small crates. This is not only troublesome for the owners, but also disruptive to the normal habits of the animal, entailing distressful and unhealthy conditions for the animals. When cold conditions persist for a long period, the quality of life of both animal and owner is severely diminished.
Heating devices have been developed for keeping small animals warm, but these have focused on indoor pets. For example, there are known in the art birdcage heaters, small animal incubators, and indoor basking beds. There are heating pads for animals to lay on, but these are also intended principally for indoor use and would provide minimal protection if used outdoors. One invention specifically intended for outdoor use is a climate-controlled doghouse with an installed heating and air conditioning unit. However, that construction is complex, expensive, and the heating and air conditioning unit cannot be used separable from the doghouse.
The present invention is directed to a simple, safe heating device that addresses the problems described above. The heating device of the present invention is compact and easily installed or removed, simple and inexpensive, and durably formed for outside use.
One aspect of the present invention is to provide a device for heating an enclosed space of the type used for sheltering small animals, in which a heating element is in electrical communication with an external electrical power supply, and for which a protective cover is provided. The protective cover includes fins which allow heat to be transferred to the enclosed space of the animal shelter without attaining an outer surface temperature that is harmful to the touch should the animal come in contact with it.
At least one heating element is housed within the protective cover. The heating element is desirably a resistance coil, but may also be an incandescent bulb or other resistive element known in the art that may be suitably configured and disposed within the protective cover. A heating element related between about 40 and 100 watts, with about 60 watts being desirable, provides an effective head load to transfer heat through the protective cover to an average enclosed space of about 20 to 25 cubic feet having about one-half inch of polystyrene insulation on the outer walls, without creating a protective cover temperature that is hurtful to the touch. As those knowledgeable of heat transfer will appreciate, the output of the heating element may be varied as the surface area and thickness of the protective cover, and the insulation of the enclosed space, are varied. Consequently, the enclosed space for the animal may be enlarged. Heating elements of differing ratings may be combined with regulating devices to achieve a desired thermal output.
A socket and connector are provided for electrically joining the heating element to an external electrical power source such as a standard 110-volt outlet. The connector may be a conventional power cord. Desirably, since the heating device of the present invention is intended for outdoor use, the connector is moisture-proof. To protect the animal from electric shock, the connector may include a protective outer casing to prevent an animal from gnawing or chewing into the connector. The connector may further include a thermostatic controller that is either attached to the protective cover or placed in electrical communication with the external power supply.
In one embodiment of the present invention, the protective cover is box shaped and is formed of a highly thermally conductive material such as aluminum, alloys of aluminum, stainless steel, or iron. Other suitable thermally conductive metallic and non-metallic materials known in the art may be used for forming the protective cover. The base of the protective cover is preferably removable to facilitate access within the protective cover for the changing of heating elements, but may be welded or otherwise sealed.
In a second embodiment, the protective cover is generally cylindrical with fins spaced along the length. In all other respects, other than shape, this embodiment is functionally similar to the first embodiment.
As described hereinabove, the heating element of the present invention is so rated and the protective cover so shaped to provide sufficient heat transfer to an enclosed space without creating a surface temperature on the protective housing that is harmful to the touch. As such, the construction described herein limits the outer surface temperature of the heating device to a temperature less than about 200 degrees Fahrenheit, and desirably no greater than about 180 degrees Fahrenheit.
These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments, when considered in conjunction with the drawings. It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.